CVE-2024-56699 s390/pci: Fix potential double remove of hotplug slot
A race condition in the s390 PCI subsystem could lead to a double removal of a hotplug slot, potentially causing a kernel crash or denial of service.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2024-56699?
CVE-2024-56699 is a high-severity vulnerability in Linux kernel, published on 28 Dec 2024. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
In the Linux kernel, the following vulnerability has been resolved:
s390/pci: Fix potential double remove of hotplug slot
In commit 6ee600bfbe0f ("s390/pci: remove hotplug slot when releasing the device") the zpci_exit_slot() was moved from zpci_device_reserved() to zpci_release_device() with the intention of keeping the hotplug slot around until the device is actually removed.
Now zpci_release_device() is only called once all references are dropped. Since the zPCI subsystem only drops its reference once the device is in the reserved state it follows that zpci_release_device() must only deal with devices in the reserved state. Despite that it contains code to tear down from both configured and standby state. For the standby case this already includes the removal of the hotplug slot so would cause a double removal if a device was ever removed in either configured or standby state.
Instead of causing a potential double removal in a case that should never happen explicitly WARN_ON() if a device in non-reserved state is released and get rid of the dead code cases.
Weakness: CWE-415
Which versions are affected by CVE-2024-56699?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2024-56699?
Apply the vendor's patch.
Is CVE-2024-56699 being exploited?
There is no known exploitation of CVE-2024-56699 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as BELL-CVE-2024-56699, DEBIAN-CVE-2024-56699, GHSA-4pr7-h3p8-c732, UBUNTU-CVE-2024-56699.